Today there is an increasing global desire to reduce greenhouse gas emissions and develop clean alternative vehicle fuels. Methane (CH4), the primary component of natural gas, is of particular interest as it is abundant and has lower CO2 emission and more efficient combustion than other hydrocarbons due its high H/C ratio. In addition to industry-driven demand for stationary gaseous storage, global governmental initiatives have created incentives to develop vehicular gaseous fuel storage.
Gas storage in porous materials has experienced significant development in recent years in various industrial applications related to energy, environment, and medicine. Among porous materials, metal organic frameworks (MOFs) are a versatile and promising class of crystalline solid state materials which allow porosity and functionality to be tailored towards various applications. MOF crystal chemistry uses a molecular building block (MBB) approach that offers potential to construct MOFs where desired structural and geometrical information are incorporated into the building blocks prior to the assembly process. Choosing an ideal blueprint net and isolating the reaction conditions that permit in situ consistent formation of the corresponding inorganic MBBs are the keys for successfully implementing this approach.
The challenges of constructing MOFs having tailored properties for gas storage applications have limited the use of low cost materials such as aluminum and iron. In particular, low cost materials have not been developed which satisfy the Department of Energy (DOE) CH4 gravimetric uptake target of 700 cm3 STP/g (0.5g/g) at recommended temperatures between −40° C. and 85° C.